C. Experimental
Explanation - The cause and effect of a process would be studied in experimental investigations. However, in descriptive studies, relationship between the factors are not studies rather the detail of the process is studied. In comparative investigation, several factors are compared and its effects are analyzed.
In experimental investigations, experiments are carried out based on the hypothesis and then it is validated accordingly. Validation is a must to prove and disprove the hypothesis. Therefore, experimental data and hypothesis are related.
C) Lactic acid and energy
This is the reason we feel a burning sensation during strenuous exercise.
Answer
Two structures located in the diencephalon are hypothalamus and epithalamus
Explanation
The diencephalon of the human brain has four main structures which are the hypothalamus, the thalamus, the epithalamus and the subthalamus. Thalamus structure is at the center of the brain which relays sensory impulses to the cerebral cortex. The hypothalamus regulates the temperature of the body while the epithalamus maintains the circadian rhythms.
Answer:
it contains and protects the cell's DNA
